As mobile communications technologies develop and a quantity of people who use mobile data services increases, load of an existing macro cell is increasingly heavy. In order to provide better services for users, a carrier aggregation (Carrier Aggregation, CA for short) technology is introduced in the 3rd Generation Partnership Project (the 3rd Generation Partnership Project, 3GPP for short).
In the CA technology, multiple base stations may be used to provide a service for a same UE. For example, a small cell and a macro base station may be used to provide a service for a UE in a cooperative manner. The small cell may be, for example, a home eNodeB (HeNB for short), a pico base station (pico for short), or a radio remote head (RRH for short). A coverage area and transmit power of the small cell are relatively small, and a coverage area of the macro base station is wide and transmit power of the macro base station is relatively large. In terms of functions, the macro base station can provide wide coverage and is responsible for controlling signaling, and the small cell can enhance user data and is responsible for all or some user service data.
However, in a scenario in which the small cell and the macro base station jointly bear transmission of a same data service of a user, a user equipment (UE for short) needs to send uplink data to the small cell and the macro base station separately. In the prior art, the small cell and the macro base station cannot accurately learn a buffer status report (hereinafter referred to as BSR) reported by the UE. Because data of the UE is sent to the small cell and the macro base station separately, and BSRs of all data in a buffer of the UE cannot be applied to a scenario in which multiple base stations serve the UE. As a result, the small cell and the macro base station cannot perform scheduling in a timely manner.